Hoist



March 6, 1934. R. M. ROBERTSON HOI ST Filed March 26, 1931 sSheets-Sheet 1 ATTORNEY l NVENTOR ROBERT M. ROBERTSON 9 R M. RQBERTsN1,99%)

HOIST Filed March 26, 1931 3 Sheets-Sheet 2 INVENTOR Ragga?" M.ROBERTSON J Q5 I 3%?TORNEY 9 I I March 6, 193%. R. M. ROBERTSON HOISTFiled. March 26. 1931 '3 Sheets-Sheet 3 5 L INVENTOR Bog M fioammozv z,AT l' a mu 7.

ORNE Y g E V Patented 6,-

um'rso s'rArl-zs PATENTll or'rlca HOIS'I' Robert M. Robertson. Toronto,Ontario, Canada,

assignor to Riley Engineering & Supply Co. ltda'goronto, Ontario,Canada, a corporation of Application March 26, 1931, Serial No. 525,478

7 Claims. (Cl, 254-171) This invention relates to hoists, and more Inaccordance with my invention I provide a particularly to hoists of thetype utilizing a hoist having a supporting frame in which a driverotatable drive shaft extending through a hollow shaft is rotatablymounted. A hollow load wheel load wheel carrying the chain or cable, thedrive surrounds the drive shaft and is rotatably mountshaft beingconnected to rotate the load wheel, -ed thereon. In the preferred form,the drive w usually by means of a train of gears. shaft and the loadwheel are mounted on rolling Ithas already been recognized that theefllbearirms which are so arranged that the forces ciency and durabilityof such hoists could be due to the load may be transmitted to the frameimproved by mounting the various rotatableparts without impartingsubstantial bending moments on bearings of the rolling type, such asball or to the shaft; The drive shaft is connected to Q5 rollerbearings. However, all prior constructions rotate the load wheel througha suitable speed of which I am aware have beenso arranged that changingmechanism such as a spur gear train. the races of the load wheelbearings must nec- The drive shaft may be suitably pe a- Such essarilybe of larger diameter. Such large dias by a han wh l h v n endlss n 13ameter bearings not only add to the bulk of the thereon, as is usual inthis art, and the load wheel 7 whole mechanism but they are also veryexpenmay be connected by means of a load chain to the sive and for somepurposes their cost is prohibiweight which i to be raised. The be rintive. In an effort to reduce the bearing sizes, the drive shaft and loadwheel may be lubricated many hoists have been made with small diameterby grease which is forced along a duct in the drive shafts, and theseshafts have frequently drive shaft by a grease cup or other pressurepro- 75 broken when the hoist has been dropped upon duclng means. thefloor. v Referring to the drawings illustrating one em- Itis'accordlngly one object of the present inbodlmentof the invention andin which like ref-- vention to provide a hoist which is so arranged renn m r indicate like P s: 7 that all rotatable parts are mounted onbearings Fi 1 is a i n through handp t of small diameter andparticularly to provide a chain hoist f th p r gear yp h c n hoist inwhich the load wheel is mounted on rollbeing taken'on the line 1-1 ofFig. 3; ing bearings having races of comparatively small 2 is a f amentary ew of a po tion of the diameter and the drive shaft isnevertheless of ratchet and its cooperating pawl taken on h sufllcientsize to avoid any danger of accidental line 2-2 of Fig. 1; a

breakage thereof. Fig. 3 is a section on the line 3-3 of Fig. 1;

It is a further object of the invention to pro- Fig. 4 is a section onthe line 4-4 of Fig. 1: and vide a hoist in which undesirable frictionlosses Fig. 5 is 8- ecti n through the p 8 m chare reduced to a minimum,and which is proanlsm, taken on the lin -5 0! F 4- 5 vided with bearingsand associated parts so ar- The embodiment illustrated in the drawingsranged that the various loads are transmitted compri s thr fl Plates 11811d 12 which without causing distortion or binding. are rigidlyconnected to form a supporting frame,

It is a further object of the invention to proand whichare preferablymade of steel, in order vide a hoist which will be comparatively lightto obtain the necessary strengthand resistance a and compact, and yethave ample capacity to to shock-with a minimum of size and weight.

handle the loads for which it is designed. These plates are arranged inspaced parallel ver- It is a further object to provide a hoist whichtical planes. Two long bolts 14 extend through will be simple andinexpensive to manufacture, all three of the plates at the upperportions thereand which will operate efficiently and without of, andbetween the plates these bolts are sur- 45 repairs throughout along lifeof usefulness. rounded by-sleeves or collars 15 and 16 which It is afurther object to provide a hoist havserve as distance pieces tomaintain the desired ing a simple and elfective means for lubricatingspacing. The plates 11 and 12 are connected at the various parts, andwhich is so arranged that their lower portions by two screws 18 whichare the lubricant will be retained in contact with the surroundedbetween the plates by spacing sleeves o bearings and all dirt and gritwill be excluded. 19. The entire supporting frameof the hoist is Withthese and other ohEe-cts in view as will arranged tobe suspended fromanysuitable overbe apparent to those skilled in the art, my invenheadstructure by means of a strong steel hook ticn resides in thecombination of parts set forth 21 which is fastened by a nut 22 to ahorizontal in the specification and covered by the claims cross head 23havingizyllndrical ends mounted in 55 appended hereto. openings in theplates 11 and 12.

A horizontal drive shaft 25 extends through the frame and is rotatablymounted therein. For

this purpose I utilize bearings of the rolling type,

thereby largely eliminating friction and wear. In the drawings, I haveshown a ball bearing 26 having its outer race mounted in a flangedferrule 27 supported in an opening in the first plate 10. The inner raceof the bearing 'is a snug fit on the drive shaft. An additional ballbearing 29 is provided with its outer race mounted in a flanged ferrule30 supported in an opening in the third plate 12. The inner race of thebearing 29 is likewise a snug fit on the drive shaft. These bearings 26and 29 are spaced a considerable distance apart so that the drive shaftis firmly supported in the frame. Z-shaped in cross-section and soarranged that they receive any end thrust which may be transmitted tothe drive shaft. While the ball bearings are designed primarily forradial loads, they have grooves of suflicient depth to withstand anythrust load which may arise incidentally during operation of the hoist.

A hollow load wheel 32 surrounds the drive shaft 25 between the bearings26 and 29, and this wheel is provided with a pocketed circumferentialgroove 33'shaped to fit the links of a heavy load chain 34. The groove33 is preferably directly beneath the supporting hook 21. One end of theload chain is fastened to the frame plates 10 and 11 by means of anchorpins 36 and 37 (Fig. 3), and the other end is arranged to be connectedto the load, usually by means of a hook (not shown). As the load wheelis rotated in a clockwise direction in Fig. 3 to raise the load, theextra length of chain will loop downwardly. A chisel shaped stripper 38extends into the chain groove 33'beheath" the load wheel and preventsthe chain links from sticking in the groove and kinking the chain. Thisstripper 38 is mounted on a pin 40 and a stud 41 extending between theframe plates 10 and 11. Spacing sleeves 42 on the stud position thestripper laterally and render the whole frame more rigid.

The load wheel 32 is rotatably mounted on the drive shaft by means ofrolling bearings. For this purpose I have shown a pair of ball bearings44 and 45, each with its outer race mounted inside the load wheel andits inner race snugly fitting the drive shaft. The inner races of thesebearings are separated by a spacing sleeve 46 on the shaft. Bearing 44is mounted closely adjacent to bearing 26, and bearing 45 is nearbearing 29, so that the load wheel bearings transmit, load to the driveshaft bearings without imparting a substantial bending moment to thedrive shaft. As a result the drive shaft need not be made large indiameter. Since both the load wheel bearings 44 and 45 are mounteddirectly on the drive shaft, their diameter is determined by the size ofthis shaft rather than by the size of a large load wheel-hub as incertain prior art constructions. This is a very important feature of thepresent invention, and results in greatly reducing not only the cost ofmanufacture but also the and weight of the mechanism. The chain groove33 is located near bearing 44 in a direction longitudinal of thedriveshaft, and as a result the major part of the force due to the weight ofthe load being lifted is transmitted to bearing 44 and thence to thedrive shaft without imparting a substantial bending moment to the loadwheel. The load wheel can therefore be made comparatively small andlight without sacrifice of strength.

The ferrules 2'7 and 30 are In-order to transmit power from the driveshaft 25 to the load wheel 32, I provide a spur pinion 47 on the driveshaft. The teeth of this pinion are preferably integral with the shaftand located between the bearings 45 and 29, which are spaced apart adistance equal to the width of the teeth. The pinion 47 meshes with apair of spur gears 48, one of which is mounted at each side of thepinion and arranged to rotate about an axis parallel to the drive shaftaxis and preferably in the same horizontal plane. Each gear 48 is keyedto a shaft 49 having a pinion 51 thereon which is preferably integralwith the shaft. The gears 48 and pinions 51 thus form a pair of clusteror compound gears. The pinions 51. both mesh with a gear 52 mounted onthe load wheel 32. While gear 52 might be made integral with the loadwheel, it is preferably made separate for convenience in assembling theparts and it is fastened to the wheel by means of pins 53. Since thebearing 45 is located Within the gear 52, it will support the load wheeldirectly against any radial load imparted to the gear. Likewise thebearing 29 will receive directly any radial load imparted to pinion 47.

The shafts 49 which carry the compound gears are rotatably supported inthe hoist frame, and for this purpose I preferably provide a ballhearing 55 for the inner end' of each shaft and a ball bearing 56 forthe outer end of each shaft (Fig. 5). Each bearing 55 has its inner racemounted on the shaft and its outer race mounted in a flanged cup 57supported in an opening in the second frame plate 11. Each bearing 56has its inner race mounted on the shaft and its outer race mounted in aflanged ferrule 58 supported in an opening in the third frame plate 12.The flanges on the cups 57 and ferrules 58 prevent endwise movement ofthe bearings, and the bearings are of a type to withstand any slight endthrust encountered during operation.

The entire spur gear mechanism is preferably enclosed by a cup-shapedcircular cover 60 of thin sheet metal which fits tightly on the outerperiphery of the second frame plate 11. This cover is held in positionby the bolts 14 and the screws 18. Spacing collars 61 (Fig. l) areplaced over these fastening members between the cover 60 and the thirdframe plate 12.

In the embodiment illustrated, I have shown the hoist arranged formanual operation by means of a hand wheel 63 provided with a peripheralchain groove 64. An endless hand chain 65 is mounted in the groove 64,and a stationarychain guard 67 supported from the hoist frame preventsfouling of the chain. The hand wheel 63 is screw threaded to the outerportion of a hub 68 having an integral flange 69 at its inner end. Thisflanged hub is fastened to the drive shaft 25 by means of a key '71, theflange 69 being located close to the bearing 26 and just outside of theframe plate 10. A flanged member 72 is threaded to the outer end of thedrive shaft, which is preferably reduced in diameter to form a shoulder,and a pin 73 prevents accidental separation of these parts. The member72 projects outside the hand wheel hub and prevents the hand wheel frombeing unscrewed from the hub 68, while allowing a slight relativemotion.

A flat annular ratchet plate 75 is mounted on the hub 68 between thehand wheel 63 and the flange 69, and this plate is separated from theflange by an annular friction plate 76 of fiber, leather, or othersuitable material. The ratchet plate is providedwith ratchet teeth 77 onits outer periphery which cooperate with a pawl '79 to prevent reverserotation of the -plate. The pawl "19 is pivoted to the frame plate 10 bymeans of a screw (Fig. 2), and urged into engagement with the teeth '17by a spring 81. The ratchet plate '35 is preferably formed with anintegral laterally projecting flange 82 which surrounds the frictionplate 76 and protects the friction surfaces from external dirt and grit.

In order to provide a simple and effective means for lubricating thevarious parts of the hoist, I form the drive shaft with a longitudinallyextending duct through which grease may be forced under'pressure. Such aduct may be com veniently provided by a drilled passage 84 at the end ofthe drive shaft which leads to a groove 85 extending along the outersurface of the shaft. A grease cup 86 screw threaded to the flangedmember 72 provides a suitable means for supplying grease to the duct.The groove 85 extends as .far as the sleeve 46, which is notched toavoid obstructing the groove and provided with an car 83 bent inwardlyinto the groove to prevent turningof the sleeve relative to the shaft.Passages 89 leadfrom the groove 85 to the screw threads on hub 68 and tothe friction plate 76. Grease is forced along the groove 85 to thebearings 44 and 26, and also passes through the space between sleeve 46and load wheel 32 to-lubricate bearings 45, pinion 47, and bearing 29.Any excess grease forced into the hoist serves to replenish the supplyin the gear casing 60, which is packed with a liberal quantity atassembly.

For the purpose of retaining the grease and preventing entry of dirt orgrit, I preferably provide a ring 90 of felt or other suitable materialwhich fits in an annular groove in the inner .face of flange es andcontacts. with the outer surface of plate 20. A similar felt ring 91 isprovided at each side face of the load wheel 32 to contact with theadjacent surfaces of plates 1d and 11.

The operation of the invention will now be apparent to those skilled inthe art. The load chain 34: attached to the load which is to be raised,and hand wheel 63 is rotated by means of hand chain 65. This advancesthe hand wheel along screw threads on. hub 68 and clamps the ratchet dsc '35 tightly between the hand wheel and the friction plate 76. Theseparts then rotate as a unit with the drive shaft, and the ratchet teeth7? click idly under the pawl 79. Pinion at on the drive shaft rotatesgears 48 and pinions 51, which in turn drive gear 52 and load wheel 32at a greatly reduced speed. The load wheel raises the load chain 34 andthe load attached thereto. When the operator ceases to rotate the handwheel, the load will remain stationar reverse movement being preventedby the pawl 79. 3 it isdesired to lower the load, hand wheel as isrotated in the reverse direction. This unclanips the ratchet disc '75and allows the load to lower under the influence of gravity, the ratch-=at disc being held stationary by the pawl. The load will lower only inaccordance with the rate at which the hand wheel is rotated, forwhenever the load tends to lower-too fast the hub d3 will screw into thehand wheel and clamp the ratchet disc against the friction plate 76,thus retarding the load. The flanged member 72 provides for positiverotation of the drive shaft to lower the load chain when "there is noload attached thereto. Under these conditions the hand wheel willunscrew from the hub 68 until it strikes the member 72, whereupon itwill positively operate'the shaft 25 and lower the load chain.

All the movingv parts are mountedfii 11 ball bearings, so that frictionand wear are practically eliminated. The bearing races are all ofcomparatively small diameter, which greatly reduces the cost and thespace required. Each bearing is so located that it receives its loaddirectly without imparting undesirable bending moments to the variousparts. By utilizing the two compound gears on opposite sides of thedrive shaft the load is balanced and the radial load on the drive shaftand load wheel bearings is greatly reduced. The grease cup 86 provides asingle accessible and convenient means for lubricating all the movingparts of the hoist. The entirev hoist is of great strength relative toits size and weight,

and it is simple and inexpensive to manufacture.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. A hoist comprising a supporting frame, a rollingbearing mounted inthe frame, a horizontal drive shaft rotatably mounted in said bearing, asecond rolling bearing mounted on the drive shaft closely adjacent tothe first mentioned bearing and arranged to transmit its load theretowithout imparting a substantial bending moment to the drive shaft, ahollow load wheel surrounding the drive shaft and rotatably supported onsaid second bearing, and means to transmit power from the drive shaft tothe load wheel.

2. Ahoist comprising a supporting frame, a rolling bearing mounted inthe frame, a horizontal drive shaft rotatably mounted in said bearing, asecond rolling bearing mounted on the drive shaft closely adjacent tothe first mentioned bearing, a hollow load wheel surrounding the driveshaft and rotatably supported on said second bearing, said load wheelhaving a chain groove in its outer periphery which is near said secondbearing ina direction longitudinal of the drive shaft, a load chainsupported in said groove, and means to transmit power from the driveshaft to the load wheel, the parts being so arranged that the forceimparted to the load chain by a load will be transmitted to the framewithout imparting a substantial bending moment to either the load wheelor the drive shaft. 1

8. A hoist comprising a supporting frame, a

' pair or" rolling bearings mounted in the frame and spaced aconsiderable distance apart, a horizontal drive shaft rotatably mountedin said beanings, a second pair of rolling bearings mounted on the driveshaft between the first mentioned bearings, a hollow load wheelsurrounding the drive shaft and rotatably supported on said second pairof bearings, and means to transmit power from the drive shaft to theload wheel, each of said second pair of bearings being located near oneof the first pair of bearings and arranged to transmit load theretowithout imparting a substantial bending moment to the drive shaft.

4. A hoist comprising a supporting frame, a pair of rolling bearingsmounted in the frame and spaced a considerable distance apart, ahorizontal drive shaft rotatably mounted in said bearingaa pinion on thedrive shaft between the bearings and close to one of the bearings, asecond pair of rolling bearings mounted on the drive shaft between thefirst pair of bearings, one of the second pair of bearings being closeto one of the first pair, and

the other of the second pair of bearings being 5. A hoist comprising asupporting frame, a pairof rolling bearings mounted in the frame andspaced a considerable distance apart, a horizontal drive shaft rotatablymounted in said bearings, a second pair of rolling bearings mounted onthe drive shaft between the first pair of bearings, a hollow load wheelsurrounding the drive shaft and rotatably supported on the second pairof bearings, a spur pinion on the drive shaft between one of the firstmentioned hearings and the adjacent bearing of the second pair, a spurgear on the load wheel, and a compound gear connecting the drive shaftpinion with the load wheel gear.

6. A hoist comprising three plates arranged in spaced vertical planesand connected to form a rigid supporting frame, a rolling bearingmounted in the first plate, a rolling bearing mounted in the thirdplate, a horizontal drive shaft rotatably mounted in said bearings, apinion on the drive shaft between the bearings and closely adjacent tothe bearing in the third plate, a second pair of rolling bearingsmounted on the drive shaft between the bearing in the first plate andthe pinion,

a hollow load wheel surrounding the shaft and I plates to form a rigidsupporting frame, a rolling bearing mounted in the first plate, arolling bearing mounted in the third plate, a horizontal drive shaftrotatably mounted in said bearings, a spur pinion on the drive shaftbetween the bearings and closely adjacent to the bearing in the thirdplate, a second pair of rolling bearings mounted on the drive shaftbetween the bearing in the first plate and theppinion, a hollow loadwheel surrounding the shaft and rotatably supported on the second pairof bearings, a spur gear on the load wheel between the second and thirdframe plates, and a compound gear at each side-of the drive shaftconnecting the drive shaft pinion with the load wheel gear, each of saidcompound gears being rotatably supported in hearings on the second andthird frame plates.

ROBERT M. ROBERTSON.

